Metal forming apparatus



Aug. 3, 1965 E. c. HALL METAL FORMING APPARATUS 2 Sheets-Sheet 1 Filed March 15, 1963 INVENTOR EDWARD 0. HALL I J- I)! A ORNEY 1965 E. c. HALL 3,198,933

METAL FORMING APPARATUS Filed March 15, 1963 2 Sheets-Sheet 2 FIG. 3.

STATION OPERATION BEGINNING :1 RAW srocx 2/ :0 HEAD 22' :4) UNDERS/DE HEAD 23 :D ROUND HEAD 24 2:13) cu HEAD 25 llllflllilllllllllllll. H/PEA D 26 :l curoFF INVENTOR E DWARO 6. HALL TTORNEY United States Patent 3,1?3933 METAL FiERMEl IG APPARATUS Edward 6. Hall, Holden, Mass. Hall line as Dewey St, Worcester, Mass.) lFiied Mar. 15, 1963, Ser. No. 265,486 3 Ciaims. Ci. 219-154) This invention relates to a metal forming apparatus, and, more particularly, to apparatus arranged to produce upset metal objects.

There are many instances in the manufacture of machinery and the like when a part to be manufactured has an enlarged portion in the form of a head at one end or in the intermediate part. it is common practice to make such articles on an automatic screw machine of the multiple-spindle type, but in present practice this operation requires the use of a bar which has a dimension at least equal to the enlarged portion. This means that the metal which must be removed from the bar to produce the portions of smaller size is wasted. Also, there are many articles in which the reduced or smaller portion of the article could make use of the surface of the original bar (so far as smoothness, finish, and size is concerned) without additional machining; however, under present methods of manufacture, it is impossible to make use of a bar of this size without making the part in two pieces. Furthermore, when a part is made with an enlarged portion, as has been described above, by removing metal from a large bar, the fibres of the metal, which normally run parallel to the axis of the bar, are cut. This produces a head which is weak in shear. These and other ditficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.

It is, therefore, an outstanding object of the invention to provide a metal forming machine for producing an article with an enlarged portion without the waste attendant upon using a bar of large diameter as the starting blank.

Another object of this invention is the provision of a metal forming machine in which an article may be produced with an enlarged portion in which the metal fibres are not cut but fiow smoothly out of a reduced portion into an enlarged portion to produce a very strong article.

A further object of the present invention is the provision of a metal forming machine which is capable of producing articles with enlarged portions less expensively and yet stronger than has heretofore been produced on automatic screw machines.

It is another object of the present invention to provide a metal forming machine consisting of a multiple-spindle automatic screw machine in which one of the stations is provided with heating apparatus and apparatus for upsetting a workpiece.

It is a further object of the invention to provide a metal forming machine consisting of metal heating and upsetting apparatus particularly adapted for use as an accessory with a conventional multiple-spindle screw machine.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

The character of the invention, however, may be best understood by reference to one of its structural forms as illustrated by the accompanying drawings in which:

FIG. 1 is a perspective view of a metal forming machine embodying the principles of the present invention,

FIG. 2 is a sectional view of the machine taken on the line 11-11 of FIG. 1,

FIG. 3 is a generally schematic view of certain electrical and hydraulic elements of the machine, and

3,198,933 Patented Aug. 3, 1965 FIG. 4 is a chart showing the operation of the machine on a typical workpiece.

Referring first to FIG. 1, wherein are best shown the general features of the invention, the metal forming machine, indicated generally by the reference numeral 10, is shown as made up of a multiple-spindle automatic screw machine 11 and a heating and upsetting apparatus 12. The screw machine 11 is of the conventional type having an elongated base 13 on which is mounted a workhead 14 at one end, a tool head 15 at the other end, and a drive motor 16. Mounted in the workhead is a circular plate 17 which is arranged to be rotatably indexed about a central horizontal axis 18 in increments of 60. For the purposes of this description, the words longitudinal, transverse, axial, and the like have reference to the axis 18.

Mounted on the plate 17 and extending therethrough are six stations including a first station 21, a second station 22, a third station 23, a fourth station 24, a fifth station 25, and a sixth station 26. Each of these stations includes a hollow spindle through which bar stock may be introduced into the machine and a collet or chuck for grasping and rotating the bar stock after it has been admitted into the work area a desired distance. Extending longitudinally and coaxially of the axis 13 from the tool head 15 is a ram 27 formed with ways to receive tool-holding apparatus. The ram 27 is moved longitudinally after each occasion that the station plate 17 is indexed 60 and this movement brings the tools which are mounted in the ways into contact with the workpieces in the various stations. To clarify the illustrations, the stations are not shown as provided with their rotating spindles and chucks, nor are the tools shown mounted on the ram 27. In addition, on the face of the workhead 14 are provided a number of cross-feed arrangements, such as the cross-feed 28 which, in most cases, would carry the cut-off tool for severing the finished workpiece from the main body of the bar. In particular, on the upper surface of the base 13 is mounted a horizontal cross-feed apparatus 29 having mounted on its upper surface a table 31 having T-slots to permit the mounting of equipment.

Mounted on the front surface of the base 13 are two containers, 32 and 33. The container 32 contains hydraulic apparatus, while the container 33 contains heating apparatus which is shown as being of the resistance type. Mounted on the table 31 of the cross-feed apparatus 29 is a clamping electrode 34, while mounted on the ram 27 in alignment with the axis of the first station 21 is an upsetting electrode 35.

The clamping electrode 34 consists of a base 36 which is fastened to the table 31 and from which extends an abutment 37. Mounted on the base 36 is a linear actuator, such as an hydraulic cylinder 38, which is connected to the hydraulic container 32 by hydraulic conduits 39 and 41. Extending from the cylinder transversely of the axis 18 is a piston rod 42 having at its outer end a toggle 43. This toggle operates on tail portions of clamping jaws 44 and 45, these jaws being pivotally mounted on horizontal, longitudinal axes on the abutment 37. The jaws are provided with opposed contact surfaces of the same diameter as the rod to be operated on in the machine.

The upsetting electrode 35 is made up of a retaining member 46 which is mounted in a way on the ram 27. The retaining member holds a linear actuator, such as a hydraulic cylinder 47. From the rear end of the cylinder 47 extends a conduit 48, the other end of the conduit 48 being connected to the hydraulic container 32. To the other end of the cylinder is connected a conduit 50, also running to the container. Extending from the cylinder 47 is a piston rod 51 having a transverse pad 52 mounted at its outer end.

Referring now to FIG. 3, which shows schematically the electrical and hydraulic apparatus forming part of the invention, it can be seen that the clamping electrode 34 and the upsetting electrode 35 are inter-linked by various electrical and hydraulic lines and connected to the hydraulic container 32 and the heating apparatus container 33.

The conduits 41 and 42 leading away from the cylinder 38 are connected to output ports of a solenoid valve 53 which is connected by an input conduit 54 to a pump 55 driven by an electric motor 56. The valve 53, the pump 55, and the motor 56 are contained in the hydraulic container 32, a sump 57 being also provided for the return of hydraulic fluid to zero pressure. A drain conduit 58 leads from the valve 53 to the sump 57. The solenoid valve 53 is operated by the energization of a solenoid coil 59. Similarly, the cylinder 47 is connected through the conduits 4S and 50 to a solenoid valve 61 which is actuated by the energization of a solenoid coil 62. The valve 61 is connected to the high-pressure side of the pump 55 by a conduit 63, while the drain portion of the valve is connected by a conduit 64 to the sump 57. In this connection, it should be noted that the base 36 on which the clamping electrode and associated apparatus are mounted is subjected to cross-feed by a conventional means such as a rotatable cam 65 contained in the cross-feed apparatus 29. Similarly, the ram 27 is moved back and forth longitudinally during each cycle by means such as a rotatable cam 67. As the ram 27 approaches its closest position to the Workhead 14, it engages a normally open limit switch 67 and closes it. Similarly, when the clamping electrode 34 approaches its closest position to the first station 21 it engages and closes a normally-open limit switch 68. The switches 67 and 68 would probably, in practice, be mounted in the body of the machine where they would be contacted at the same time in the cycle by transmission elements; they are shown in exposed positions for the sake of clarity of description. The electrical apparatus in the container 33 consists of two power lines 65 and 71 connected to a source 72 of alternating current electricity. The electric motor 56 is connected by lines 73 and 74 to the power lines 69 and 71, respectively. One side of the coil 62 is connected by a line 75 to the power line 69. The power line 71 is connected to one side of the limit switch 67 by a line 76 and the other side of the limit switch 67 is connected to the other side of the coil 62 by a line 77. Similarly, one side of the solenoid coil 59 is connected by a line 78 to the power line 69, while the power line 71 is connected by a line 79 to one side of the limit switch 68; the other side of the limit switch 68 is connected to the other side of the solenoid coil 59 by a line 81. The line 69 is connected through a contactor 82 (controlled by a timer 80 or a thermostat in the well-known manner) to one end of the primary coil 33 of a step-down transformer 84, the other end of which is directly connected to the power line 71. The secondary coil 85 of the transformer is connected on one end by a cable 86 to the upsetting electrode 34 and, more specifically, to the pad 52 thereof. The other end of the coil 85 is connected by a cable 87 to the jaws 44 and 45 of the clamping electrode 34.

The operation of the apparatus will now be readily understood in view of the above description, particularly with reference to the chart shown in FIG. 4 which shows the steps of forming a typical article. A bar is introduced into the machine through the workhead 14 and specifically through the hollow spindle of the first station 21. The condition of the raw bar stock is shown as it enters the machine, is introduced into the machine a pre-determined distance, and is clamped there. In the first station 21, the stock is provided with a head 88. When the station 21 progresses to the position where the second station 22 is now located, the head is given a smooth undersurface 89. When the first station 21 is indexed another 60 to the position where the station 23 is shown, the head is provided with a round surface 91. When the plate rotates another 60 to bring the first station 21 into the position where the station 24 is now located, the head is provided with a cup surface 92. Then, the station plate 17 is rotated another 60 to bring the station 21 into the position now occupied by the station 25 and, at that time, the workpiece is provided with a thread 93. Finally, when the first station 21 moves into the position now occupied by the 6th station 26, a cut-off tool moves in to sever the workpiece from the rest of the bar. This, of course, is only a typical workpiece and many variations of the operations are contemplated. All of the operations in the places occupied by the stations 22, 23, 24, 25, and 26 are more or less conventional in automatic screw machines. However, the heading operation is novel.

Let it be assumed that the raw bar stock is in place in the first station 21 and that the ram 27 advances under the impetus of the cam 67 to bring the tools mounted on the ram into operative position relative to the various stations. So far as station 21 is concerned, the pad 52 soon impinges on the end of the workpiece. The coil 62 is unenergized so that the line 43 is connected through the valve 61 to the sump 57 by means of the conduit 64; therefore, as the ram 27 advances, the piston rod 51 and its piston will be pushed to the other end of the cylinder 47, squeezing the oil out of the cylinder to the sump. While the ram is advancing, the cam 65 moves the clamping apparatus 34 inwardly toward the workpiece. The jaws 44 and 45 are held in an open condition. Eventually, the base 36 and all the apparatus mounted on it, including the jaws 44 and 45 have been moved inwardly far enough so that the semi-circular notches in the jaws 44 and 45 are above and below the workpiece in an intermediate portion thereof. At that time, the clamping apparatus strikes the limit switch and closes it. This causes the solenoid coil 59 to be energized and operates the valve 53 to cause pressure oil to flow to the outer end of the piston and advance the piston rod inwardly toward the workpiece. This, in turn, causes the toggle to operate between the outboard ends of the jaws 44 and 45 and to press them apart so that they clamp the workpiece. At this time, the switch 532 is closed, causing current to flow through the primary coil 83 and to generate a current in the secondary coil of the transformer 84. The pad 52 presses against the end of the workpiece and the clamps 44 and 45 clamp an intermediate portion of the workpiece, so that current passes through the portion of the workpiece between these elements and causes the metal to heat. Further advancement of the ram 27 closes the limit switch 67 and causes electricity to flow through the coil 62. The energization of this coil operates on the valve 61 to cause pressure oil to flow from the conduit 63 through the valve and through the conduit 43 into the outboard end of the cylinder 47. The piston rod 51 is advanced to the left (in FIG. 3) and the pad 52 brings pressure to bear against the end of the workpiece. The workpiece, by this time, has been suificiently heated to be in a soft condition so that the pressure of the pad causes a heading or upsetting of the workpiece, bringing it into the condition shown in the chart at station 21. It will be understood that by shaping the pad 52 and the clamps 44 and 45, it is possible to bring about various locations and conformations of the head in this upsetting operation, as is well known in the art.

After the heading operation and after the other tools on the ram 27 have finished the operations which have been going on at the various stations on other workpieces, the ram 27 is withdrawn. At the same time, the clamping apparatus 34 moves outwardly; when it does so, the limit switch 63 opens to cause a de-energization of the coil 59 and to condition the valve 53 so that pressure oil is admitted to the inner end of the cylinder 38, while the outboard end is connected to discharge through the conduit 40 and the conduit 58. This retracts the toggle from between the outer ends of the jaws 44 and 45 so that they are caused to open. As soon as the ram 27 and its tools are a sufiicient distance away from the workpieces extending through the plate 17 and the clamping apparatus 34 has been moved away, the plate is rotated 60 carrying each workpiece over to the next position for another operation and a new workpiece appears at the position formerly occupied by station 21.

It will be understood that, if the upsetting operation should be desired in an intermediate portion of the workpiece, this can be accomplished by using another clamp in place of the pad 52, so that both electrodes grasp intermediate portions of the workpiece and, after the intervening parts of the workpiece have been heated, the electrodes are moved toward one another to produce the upsetting operation. It can be seen that by the use of the present invention, it is possible to use bar stock having a diameter of the threaded part of the product rather than the thick bar stock that would be dictated by the diameter of the head 88 under the present practice. Thus, a considerable waste of metal, which would necessarily be removed from the bar, is avoided. Furthermore, the upsetting operation is a forging operation, so that the grain structure and the fibres in the metal flow in uninterrupted lines from the thin body of the product into the head, thus producing a very strong article of manufacture.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come Within the scope claimed.

The invention having been thus described, what is claimed as new and desired to secure by Letters Patent, is:

1. A metal-forming apparatus, comprising (a) a multi-station workhead in which an elongated rod is introduced at a first station and is moved successively from one station to another for subsequent machining operations,

(b) a heating means including a first electrode movable from an operative position adjacent one of the stations laterally of the rod at which position the electrode makes electrical contact with the rod, to an inoperative position removed from the said station,

(c) electrical apparatus for causing the heating means to head the rod when it is in operative position, and

(d) upsetting means located at the said one of the stations in line with the rod and movable longitudinally toward and away from the rod for electrical contact with the rod in that station and including a second electrode forming part of the heating means, the upsetting means being operative when the said first electrode is in the said operative position.

2. A metal-forming apparatus as recited in claim 1, wherein the first electrode consists of a clamp movable from the operative position to the inoperative position by a hydraulic cylinder and opening and closing during that movement in order to provide for releasing or clamping the rod.

3. A metal-forming apparatus as recited in claim 1, wherein the upsetting means includes a pad extending at a right angle to the axis of the rod and movable by means of a hydraulic cylinder to make electrical contact with the rod and to provide the upsetting action.

References Cited by the Examiner UNITED STATES PATENTS 984,851 2/11 Reed 219-154 1,333,081 3/20 Kobert 219-150 1,692,488 11/28 Dannell 219-150 1,718,364 6/29 Kobert 219-150 1,878,183 9/32 Roberts 219-150 2,113,583 4/38 Finzel 219-150 2,890,325 6/59 Havlik 219-152 FOREIGN PATENTS 692,405 8/30 France.

408,903 1/25 Germany.

RICHARD M. WOOD, Primary Examiner. 

1. A METAL-FORMING APPARATUS, COMPRISING (A) A MULTI-STATION WORKHEAD IN WHICH AN ELONGATED ROD IS SUPPORTED AT A FIRST STATION AND IS MOVED SUCESSIVELY FROM ONE STATION TO ANOTHER FOR SUBSEQUENT MACHINING OPERATIONS, (B) A HEATING MEANS INCLUDING A FIRST ELECTRODE MOVABLE FROM AN OPERATIVE POSITION ADJACENT ONE OF THE STATIONS LATERALLY OF THE ROD AT WHICH POSITION THE ELECTRODE MAKES ELECTRICAL CONTACT WITH THE ROD, TO AN INOPERATIVE POSITION REMOVED FROM THE SAID STATION, (C) ELECTRICAL APPARATUS FOR CAUSING THE HEATING MEANS TO HEAD THE ROD WHEN IT IS IN OPERATIVE POSITION, AND (D) UPSETTING MEANS LOCATED AT THE SAID ONE OF THE STATIONS IN LINE WITH THE ROD AND MOVABLE LONGITUDINALLY TOWARD AND AWAY FROM THE ROD FOR ELECTRICAL CONTACT WITH THE ROD IN THAT STATION AND INCLUDING A SECOND ELECTRODE FORMING PART OF THE HEATING MEANS, THE UPSETTING MEANS BEING OPERATIVE WHEN THE SAID FIRST ELECTRODE IS IN THE SAID OPERATIVE POSITION. 